/*
 * Copyright © 2001 Red Hat, Inc.
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that
 * copyright notice and this permission notice appear in supporting
 * documentation, and that the name of Red Hat not be used in advertising or
 * publicity pertaining to distribution of the software without specific,
 * written prior permission.  Red Hat makes no representations about the
 * suitability of this software for any purpose.  It is provided "as is"
 * without express or implied warranty.
 *
 * RED HAT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL RED HAT
 * BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN 
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * Author:  Owen Taylor, Red Hat, Inc.
 */
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <X11/Xlib.h>
#include <X11/Xmd.h>		/* For CARD16 */

#include "xsettings-client.h"
#include "server.h"
#include "panel.h"
#include "launcher.h"

struct _XSettingsClient
{
	Display *display;
	int screen;
	XSettingsNotifyFunc notify;
	XSettingsWatchFunc watch;
	void *cb_data;

	Window manager_window;
	XSettingsList *settings;
};


void xsettings_notify_cb (const char *name, XSettingsAction action, XSettingsSetting *setting, void *data)
{
	//printf("xsettings_notify_cb\n");
	if ((action == XSETTINGS_ACTION_NEW || action == XSETTINGS_ACTION_CHANGED) && name != NULL && setting != NULL) {
		if (!strcmp(name, "Net/IconThemeName") && setting->type == XSETTINGS_TYPE_STRING) {
			if (icon_theme_name) {
				if (strcmp(icon_theme_name, setting->data.v_string) == 0)
					return;
				free(icon_theme_name);
			}
			icon_theme_name = strdup(setting->data.v_string);
			
			int i;
			for (i = 0 ; i < nb_panel ; i++) {
				Launcher *launcher = &panel1[i].launcher;
				cleanup_launcher_theme(launcher);
				launcher_load_themes(launcher);
				launcher_load_icons(launcher);
				launcher->area.resize = 1;
			}
		}
	}
}


static void notify_changes (XSettingsClient *client, XSettingsList *old_list)
{
	XSettingsList *old_iter = old_list;
	XSettingsList *new_iter = client->settings;

	if (!client->notify)
		return;

	while (old_iter || new_iter) {
		int cmp;

		if (old_iter && new_iter)
			cmp = strcmp (old_iter->setting->name, new_iter->setting->name);
		else if (old_iter)
			cmp = -1;
		else
			cmp = 1;

		if (cmp < 0) {
			client->notify (old_iter->setting->name, XSETTINGS_ACTION_DELETED, NULL, client->cb_data);
		}
		else if (cmp == 0) {
			if (!xsettings_setting_equal (old_iter->setting, new_iter->setting))
				client->notify (old_iter->setting->name, XSETTINGS_ACTION_CHANGED, new_iter->setting, client->cb_data);
		}
		else {
			client->notify (new_iter->setting->name, XSETTINGS_ACTION_NEW, new_iter->setting, client->cb_data);
		}

		if (old_iter)
			old_iter = old_iter->next;
		if (new_iter)
			new_iter = new_iter->next;
	}
}


static int ignore_errors (Display *display, XErrorEvent *event)
{
	return True;
}

static char local_byte_order = '\0';

#define BYTES_LEFT(buffer) ((buffer)->data + (buffer)->len - (buffer)->pos)

static XSettingsResult fetch_card16 (XSettingsBuffer *buffer, CARD16 *result)
{
	CARD16 x;

	if (BYTES_LEFT (buffer) < 2)
		return XSETTINGS_ACCESS;

	x = *(CARD16 *)buffer->pos;
	buffer->pos += 2;

	if (buffer->byte_order == local_byte_order)
		*result = x;
	else
		*result = (x << 8) | (x >> 8);

	return XSETTINGS_SUCCESS;
}


static XSettingsResult fetch_ushort (XSettingsBuffer *buffer, unsigned short  *result) 
{
	CARD16 x;
	XSettingsResult r;  

	r = fetch_card16 (buffer, &x);
	if (r == XSETTINGS_SUCCESS)
		*result = x;

	return r;
}


static XSettingsResult fetch_card32 (XSettingsBuffer *buffer, CARD32 *result)
{
	CARD32 x;

	if (BYTES_LEFT (buffer) < 4)
		return XSETTINGS_ACCESS;

	x = *(CARD32 *)buffer->pos;
	buffer->pos += 4;

	if (buffer->byte_order == local_byte_order)
		*result = x;
	else
		*result = (x << 24) | ((x & 0xff00) << 8) | ((x & 0xff0000) >> 8) | (x >> 24);

	return XSETTINGS_SUCCESS;
}

static XSettingsResult fetch_card8 (XSettingsBuffer *buffer, CARD8 *result)
{
  if (BYTES_LEFT (buffer) < 1)
    return XSETTINGS_ACCESS;

  *result = *(CARD8 *)buffer->pos;
  buffer->pos += 1;

  return XSETTINGS_SUCCESS;
}

#define XSETTINGS_PAD(n,m) ((n + m - 1) & (~(m-1)))

static XSettingsList *parse_settings (unsigned char *data, size_t len)
{
	XSettingsBuffer buffer;
	XSettingsResult result = XSETTINGS_SUCCESS;
	XSettingsList *settings = NULL;
	CARD32 serial;
	CARD32 n_entries;
	CARD32 i;
	XSettingsSetting *setting = NULL;

	local_byte_order = xsettings_byte_order ();

	buffer.pos = buffer.data = data;
	buffer.len = len;

	result = fetch_card8 (&buffer, (CARD8*)&buffer.byte_order);
	if (buffer.byte_order != MSBFirst && buffer.byte_order != LSBFirst) {
		fprintf (stderr, "Invalid byte order %x in XSETTINGS property\n", buffer.byte_order);
		result = XSETTINGS_FAILED;
		goto out;
	}

	buffer.pos += 3;

	result = fetch_card32 (&buffer, &serial);
	if (result != XSETTINGS_SUCCESS)
		goto out;

	result = fetch_card32 (&buffer, &n_entries);
	if (result != XSETTINGS_SUCCESS)
		goto out;

	for (i = 0; i < n_entries; i++) {
		CARD8 type;
		CARD16 name_len;
		CARD32 v_int;
		size_t pad_len;

		result = fetch_card8 (&buffer, &type);
		if (result != XSETTINGS_SUCCESS)
			goto out;

		buffer.pos += 1;

		result = fetch_card16 (&buffer, &name_len);
		if (result != XSETTINGS_SUCCESS)
			goto out;

		pad_len = XSETTINGS_PAD(name_len, 4);
		if (BYTES_LEFT (&buffer) < pad_len) {
			result = XSETTINGS_ACCESS;
			goto out;
		}

		setting = malloc (sizeof *setting);
		if (!setting) {
			result = XSETTINGS_NO_MEM;
			goto out;
		}
		setting->type = XSETTINGS_TYPE_INT; /* No allocated memory */

		setting->name = malloc (name_len + 1);
		if (!setting->name) {
			result = XSETTINGS_NO_MEM;
			goto out;
		}

		memcpy (setting->name, buffer.pos, name_len);
		setting->name[name_len] = '\0';
		buffer.pos += pad_len;

		result = fetch_card32 (&buffer, &v_int);
		if (result != XSETTINGS_SUCCESS)
			goto out;
		setting->last_change_serial = v_int;

		switch (type) {
			case XSETTINGS_TYPE_INT:
			result = fetch_card32 (&buffer, &v_int);
			if (result != XSETTINGS_SUCCESS)
				goto out;
			setting->data.v_int = (INT32)v_int;
			break;
			case XSETTINGS_TYPE_STRING:
			result = fetch_card32 (&buffer, &v_int);
			if (result != XSETTINGS_SUCCESS)
				goto out;

			pad_len = XSETTINGS_PAD (v_int, 4);
			if (v_int + 1 == 0 || /* Guard against wrap-around */
			BYTES_LEFT (&buffer) < pad_len) {
				result = XSETTINGS_ACCESS;
				goto out;
			}

			setting->data.v_string = malloc (v_int + 1);
			if (!setting->data.v_string) {
				result = XSETTINGS_NO_MEM;
				goto out;
			}

			memcpy (setting->data.v_string, buffer.pos, v_int);
			setting->data.v_string[v_int] = '\0';
			buffer.pos += pad_len;
			break;
			case XSETTINGS_TYPE_COLOR:
			result = fetch_ushort (&buffer, &setting->data.v_color.red);
			if (result != XSETTINGS_SUCCESS)
				goto out;
			result = fetch_ushort (&buffer, &setting->data.v_color.green);
			if (result != XSETTINGS_SUCCESS)
				goto out;
			result = fetch_ushort (&buffer, &setting->data.v_color.blue);
			if (result != XSETTINGS_SUCCESS)
				goto out;
			result = fetch_ushort (&buffer, &setting->data.v_color.alpha);
			if (result != XSETTINGS_SUCCESS)
				goto out;
			break;
			default:
			/* Quietly ignore unknown types */
			break;
		}

		setting->type = type;

		result = xsettings_list_insert (&settings, setting);
		if (result != XSETTINGS_SUCCESS)
		goto out;

		setting = NULL;
	}

	out:

	if (result != XSETTINGS_SUCCESS) {
		switch (result) {
			case XSETTINGS_NO_MEM:
			fprintf(stderr, "Out of memory reading XSETTINGS property\n");
			break;
			case XSETTINGS_ACCESS:
			fprintf(stderr, "Invalid XSETTINGS property (read off end)\n");
			break;
			case XSETTINGS_DUPLICATE_ENTRY:
			fprintf (stderr, "Duplicate XSETTINGS entry for '%s'\n", setting->name);
			case XSETTINGS_FAILED:
			case XSETTINGS_SUCCESS:
			case XSETTINGS_NO_ENTRY:
			break;
		}

		if (setting)
			xsettings_setting_free (setting);

		xsettings_list_free (settings);
		settings = NULL;
	}

	return settings;
}


static void read_settings (XSettingsClient *client)
{
	Atom type;
	int format;
	unsigned long n_items;
	unsigned long bytes_after;
	unsigned char *data;
	int result;

	int (*old_handler) (Display *, XErrorEvent *);

	XSettingsList *old_list = client->settings;
	client->settings = NULL;

	old_handler = XSetErrorHandler (ignore_errors);
	result = XGetWindowProperty (client->display, client->manager_window, server.atom._XSETTINGS_SETTINGS, 0, LONG_MAX, False, server.atom._XSETTINGS_SETTINGS, &type, &format, &n_items, &bytes_after, &data);
	XSetErrorHandler (old_handler);

	if (result == Success && type == server.atom._XSETTINGS_SETTINGS) {
		if (format != 8) {
			fprintf (stderr, "Invalid format for XSETTINGS property %d", format);
		}
		else
			client->settings = parse_settings (data, n_items);
		XFree (data);
	}

	notify_changes (client, old_list);
	xsettings_list_free (old_list);
}


static void check_manager_window (XSettingsClient *client)
{
	if (client->manager_window && client->watch)
		client->watch (client->manager_window, False, 0, client->cb_data);

	XGrabServer (client->display);

	client->manager_window = XGetSelectionOwner (server.dsp, server.atom._XSETTINGS_SCREEN);
	if (client->manager_window)
		XSelectInput (server.dsp, client->manager_window, PropertyChangeMask | StructureNotifyMask);

	XUngrabServer (client->display);
	XFlush (client->display);

	if (client->manager_window && client->watch)
		client->watch (client->manager_window, True, PropertyChangeMask | StructureNotifyMask, client->cb_data);

	read_settings (client);
}


XSettingsClient *xsettings_client_new (Display *display, int screen, XSettingsNotifyFunc notify, XSettingsWatchFunc watch, void *cb_data) 
{
	XSettingsClient *client;

	client = malloc (sizeof *client);
	if (!client)
		return NULL;

	client->display = display;
	client->screen = screen;
	client->notify = notify;
	client->watch = watch;
	client->cb_data = cb_data;

	client->manager_window = None;
	client->settings = NULL;

	if (client->watch)
		client->watch (RootWindow (display, screen), True, StructureNotifyMask,	client->cb_data);

	check_manager_window (client);

	if (client->manager_window == None) {
		printf("NO XSETTINGS manager, tint2 use config 'launcher_icon_theme'.\n");
		free (client);
		return NULL;
	}
	else
		return client;
}


void xsettings_client_destroy (XSettingsClient *client)
{
	if (client->watch)
		client->watch (RootWindow (client->display, client->screen), False, 0, client->cb_data);
	if (client->manager_window && client->watch)
		client->watch (client->manager_window, False, 0, client->cb_data);

	xsettings_list_free (client->settings);
	free (client);
}


XSettingsResult xsettings_client_get_setting (XSettingsClient *client, const char *name, XSettingsSetting **setting)
{
	XSettingsSetting *search = xsettings_list_lookup (client->settings, name);
	if (search) {
		*setting = xsettings_setting_copy (search);
		return *setting ? XSETTINGS_SUCCESS : XSETTINGS_NO_MEM;
	}
	else
		return XSETTINGS_NO_ENTRY;
}


Bool xsettings_client_process_event (XSettingsClient *client, XEvent *xev)
{
	/* The checks here will not unlikely cause us to reread
	* the properties from the manager window a number of
	* times when the manager changes from A->B. But manager changes
	* are going to be pretty rare.
	*/
	if (xev->xany.window == RootWindow (server.dsp, server.screen)) {
		if (xev->xany.type == ClientMessage && xev->xclient.message_type == server.atom.MANAGER) {
			check_manager_window (client);
			return True;
		}
	}
	else if (xev->xany.window == client->manager_window) {
		if (xev->xany.type == DestroyNotify) {
			check_manager_window (client);
			return True;
		}
		else if (xev->xany.type == PropertyNotify) {
			read_settings (client);
			return True;
		}
	}

	return False;
}

